/*
Digital Differential Analyzer (DDA) algorithm for drawing a triangle.
Code from Computer Graphics (SPPU - Second Year - Computer Engineering - Content) repository on KSKA Git: https://git.kska.io/sppu-se-comp-codes/CG
*/

// BEGINNING OF CODE
#include <iostream>
#include <graphics.h>
using namespace std;

class triangle_maker {
	
	public:
	
	int gd=DETECT, gm;
	float x1, y1, x2, y2, x, y;
	float len, dx, dy, xin, yin;
	
	// Function to make edges of triangle
	void edge(float x1, float y1, float x2, float y2){
	
	initgraph(&gd, &gm, NULL);
	
		dx=x2-x1;
		dy=y2-y1;
		
		if (abs(dx)>=abs(dy)) {
			len=abs(dx);
		}
		else {
			len=abs(dy);
		}
	
		xin=dx/len;
		yin=dy/len;
		
		x=x1;
		y=y1;
		
		int i=0;
		while (i<=len) {
			putpixel(round(x),round(y),WHITE);
			x=x+xin;
			y=y+yin;
		i++;
		}
	}
};

int main(){	

	float X1,X2,X3,Y1,Y2,Y3;
	triangle_maker obj_triangle;
	
	cout<<"Enter X coordinate for first edge:\t";
	cin>>X1;
	cout<<"Enter Y coordinate for first edge:\t";
	cin>>Y1;
	cout<<"Enter X coordinate for second edge:\t";
	cin>>X2;
	cout<<"Enter Y coordinate for second edge:\t";
	cin>>Y2;
	cout<<"Enter X coordinate for third edge:\t";
	cin>>X3;
	cout<<"Enter Y coordinate for third edge:\t";
	cin>>Y3;

	obj_triangle.edge(X1,Y1,X2,Y2);
	obj_triangle.edge(X2,Y2,X3,Y3);
	obj_triangle.edge(X3,Y3,X1,Y1);
	delay(50000);
	closegraph();
	return 0;
}
// END OF CODE